A Software Defined Network (SDN) is a new network structure. The core technology of the SDN is OpenFlow, which can implement flexible management of network flows by separating the control plane of a network device from the data plane of the network device.
A SDN controller may implement functions including the collection of network topology, the calculation of routing, the generation and distribution of flowentries, the management and control of a network. A network layer device may perform the forwarding of flows and the execution of policies.
Network Functions Virtualization (NFV) is an Industry Specification Group (ISG) of European Telecommunication Standards Institute (ETSI). In a NFV method, all kinds of network elements become separated applications, and may be deployed flexibly on a platform that is constructed based on standard servers, storages and switches.
NFV technology is based on cloud calculation and virtualization technology. A universal Commercial Off-The-Shelf (COTS) calculation/storage/network hardware device may be divided into many kinds of resources by the virtualization technology, so as to be used by various applications in an upper layer. Further, the applications may be decoupled from hardware, thereby greatly improving the supply speed of resources.
By a firewall stack technology, multiple physical firewall devices may be stacked to form a logic firewall device.